This invention refers to an angle detection device with a data transmission path of an nxc2x7360xc2x0 bearing assembly of a gyro compass, and to a gyro compass having this type of angle detection device and data transmission path.
The problems and demands arising for these bearing assemblies are described below first of all for the concrete example of use in a gyro compass.
Gyro compasses, such as those known in DE-A1 44 26 293, comprise a compass system disposed in a casing and constantly maintaining its orientation relative to the earth""s surface while in sustained rapid rotation. The casing here is attached to a support frame that can be adjusted by a tracking motor so as to match the instantaneous compass system orientation, i.e., in instantaneous angle to the casing to reduce the angle occurring between the compass system and the casing back to zero.
The absolute value of this adjustment of the casing is preferably detected as an absolute angle by electro-optical scanning of a coded marking on a scanning disk. This give the relative change in course of a vehicle such as a ship while the vehicle body turns together with the support frame connected to it, relative to the compass system with its constant orientation. The results of the electro-optical scanning are preferably fed to additional electronic processing means and finally to a display. The detection of this angle is explained in greater detail in the given publication.
The float with a compass system in a gyro compass of this kind is kept in an electrolytic fluid that is warmed up relative to the ambient temperature and is thus more viscous. The fluid is also put in motion by pumps. Up to now, the operating state of these pumps, the temperature of the fluid, and the control signals for the compass system setting and for the heating have been transmitted electrically through slipring connections. The problem with this is that especially when digital signals are usedxe2x80x94which is common practice nowadaysxe2x80x94but also in the case of analog signals, individual bits can xe2x80x9cget lostxe2x80x9d through the slipring connection, which results in totally false data transmission. Therefore, up to now the transmitted data has been examined for plausibility by complex computer programs before being fed to the tracking motor. In spite of this considerable effort, problems with false status data can still arise.
Therefore, it is an object of the invention to create a construction in which these problems do no occur and in which the response time for the adjustment can be abbreviated.
This problem is solved in accordance with the invention by a gyro compass having the features disclosed herein.
A particular advantage herein is that additional electro-optical data transmission means for the angle data are provided on the scanning disk. Together with corresponding data transmission means provided on an opposite surface, these additional means form a data transmission path-a bi-directional path in a preferred embodimentxe2x80x94which enables the accurate electro-optical transmission of data even if the scanning disk is rotated relative to the opposite surface set on the support frame.
A current from the power supply can be introduced in a conventional manner, for instance through a slipring connection. The properties of the slipring connection pose no problems here.
One emitter and one receive diode each (or a transistor) are advantageously provided in close proximity to the center of rotation of the scanning disk. Preferably even two each of the same type of components are provided directly on the axis of rotation. In this way the optical transmission pathxe2x80x94which now always extends at the same angle from the rotational axisxe2x80x94also always uses the same illumination angle of the diodes, independently of the rotational angle of the scanning disk. This ensures that no intensity fluctuations caused by varying illumination angles can occur if the scanning disk is rotated.
Aside from its use in gyro compasses, the angle detection device with a data transmission path on an nxc2x7360xc2x0 bearing assembly is suitable for any arrangements of two components together and, if applicable, also for those on which several (partial) scanning surfaces are covered by corresponding electro-optical scanning means.
The electronics for data conversion provided on the fixed componentxe2x80x94in the example of the compass, the one on the opposite side connected to the support framexe2x80x94can then be laid out in a suitable manner, as can the electronics provided on the movable component, for instance to pass data on to a CAN bus system (controller area network).